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The universal SPA2IS Programmable Limit Alarm Trips provide on/off control, warn of unwanted process conditions, alarm on rate-of-change and provide emergency shutdown. Very versatile, they accept signal inputs from transmitters and temperature
sensors that are located in hazardous areas where the method of protection implemented by the plant or facility is Intrinsic Safety.

1.
Programmable Limit Alarm Trips with
Intrinsically-Safe Field Connections
SPA2
IS
Page 1
The SPA2
IS features a metal, RFI resistant housing with display
that snaps onto standard DIN-style rails.
April 2016
Description
The universal SPA2
IS Programmable Limit Alarm Trips
provide on/off control, warn of unwanted process
conditions, alarm on rate-of-change and provide
emergency shutdown. Very versatile, they accept
signal inputs from transmitters and temperature
sensors that are located in hazardous areas where
the method of protection implemented by the plant
or facility is Intrinsic Safety (Figure 1). Normally
such installations would require the additional use of
an intrinsically-safe barrier. The SPA2
IS, however,
includes intrinsically-safe ﬁeld connections which
provide the necessary protection typically afforded by
a galvanically isolated intrinsically-safe barrier. The
SPA2
IS accepts a wide array of inputs:
• Current and Voltage Signals
• 23 RTD Types
• 9 Thermocouple Types
• Resistance and Potentiometer Devices
• Direct Millivolt Sources
Dual and Quad Alarm Trip Outputs
The 4-wire (line/mains-powered) SPA2
IS provides
two or four independent and individually-conﬁgurable
alarm relay outputs when a monitored process
variable falls outside of user-set high and/or low limits.
This is typically used to activate a warning light,
annunciator, bell, pump, motor or shutdown system.
Features
• Intrinsically-Safe Field Connections. Apply
inputs from temperature sensors or transmitters
located in hazardous areas without the need of
a costly intrinsically-safe barrier. Plus power an
intrinsically-safe loop using the 2-wire transmitter
excitation in the current/voltage input model.
• Universal plant standard. With programmable
input/output parameters, and “Universal” DC or AC
power input, there’s no need to stock dozens of
different alarm trips.
• 20-bit input resolution. Delivers industry-
best digital accuracy for both sensor (RTD and
thermocouple) and analog (current/voltage) inputs.
• Site- and PC-Programmable. Featuring security
password protection, the SPA2
IS offers the choice
of using front panel pushbuttons or our FREE
Windows®
-based Intelligent PC Conﬁguration
Software for fast and simple set up.
• Large 5-digit process and status readout. A
display shows menu prompts during pushbutton
conﬁguration and, when the SPA2
IS is in operation,
shows the process variable, the output or toggles
between the two in selectable engineering units.
• Combined alarm trip and transmitter. The
analog output (-AO) option reduces costs and
installation time when both alarm and transmitter
functions are needed at the same location.
• Long-term stability. Provides up to 5 years
between scheduled calibrations.
• Isolated and RFI/EMI protection. Delivers
superior protection against the effects of ground
loops and plant noise.
2016 Moore Industries-International, Inc.
225-710-08B
Figure 1. Available SPA2
IS models deliver versatile and
programmable input and output choices.
Programmable
Output
Dual Relay
Quad Relay
(Trip Points,
High Alarm,
Low Alarm,
Failsafe,
Non-Failsafe,
Normally Open,
Normally Closed)
Analog Output
(optional)
Universal 4-Wire
(Line/Mains) Powered
21.6-125Vdc or 90-260Vac
Programmable
Input
mA
V
RTD
T/C
ohms
mV
16.248
MA
Hazardous Area
Class I, Div I/Zone 0,1
Safe Area
or Class I, Div 2/Zone 2
Certiﬁcations
IECEx

2.
Programmable Limit Alarm Trips with
Intrinsically-Safe Field Connections
SPA2
IS
Page 2
The disadvantage of these separate IS barriers is the
installation and maintenance costs. Many of these
costs can be drastically reduced if an associated
apparatus like the SPA2
IS is used. Since the associ-
ated apparatus includes the barrier in the receiving
device there is no need for the additional cost of the
barrier, cabinet space, a high integrity clean ground
connection, separate power supply or custom vendor
backplane.
Associated apparatus incorporate a barrier into
the safe area (Class I, Div 2/Zone 2 or Unclassiﬁed)
mounted receiving device or the control room equip-
ment. The Moore Industries SPA2
IS is an example
of such a device that provides an isolating barrier
within the alarm trip (Figure 3 and 4). This dramati-
cally reduces the cost of purchase, installation and
maintenance versus more traditional approaches that
require a separate zener or isolating barrier.
SPA2
IS Associated Apparatus
An IS system installation requires a barrier or associ-
ated apparatus interface between the ﬁeld device and
the control room equipment (Figure 2). Its function is
to limit the energy to the hazardous area such that,
even under a fault condition, there cannot be enough
electrical or thermal energy released by the device to
ignite an explosive atmosphere.
Zener Diode barriers are simple passive devices
comprised of zener diodes, resistors and fuses
that serve to limit the voltage, current, and power
available to the hazardous area device. A common
downside of using this approach is that the required
earth ground has low noise rejection capability.
This electrical interference can introduce stray and
unwanted electrical noise components into the
measurement circuit creating potentially signiﬁcant
measurement errors.
Isolated barriers are active devices that incorporate
galvanic isolation thus eliminating the requirement
for an earth ground. These barriers require auxiliary
operating power and cost more than passive zener
barriers.
Hazardous Area
Class I, Div 1/Zone 0, 1
Universal
Power Supply
Safe Area
or Class I, Div 2/Zone 2
4-20mA
4-20mA - Linear Level
Diagnostic Alarm
Alarm - High Rate of Change
DCS
To Pump Control
To ESDPower
Supply
DC
4-20mA
AC/DC
READY INPUT TRIP 1 TRIP 2 TRIP 3 TRIP 4
SELECTDOWNUPCOM
16.248
MA
IntrinsicSafeBarrier
Figure 2. An intrinsically-safe
system utilizing isolated barriers.

4.
Programmable Limit Alarm Trips with
Intrinsically-Safe Field Connections
SPA2
IS
Page 4
Site- and PC-Programmable
Operating parameters conﬁgure quickly and easily
using front panel pushbuttons or our Intelligent
PC Conﬁguration Software. Programmable
functions include:
• Security password protection on/off and password
• Input type and measurement range
(zero and full scale values)
• Input and output trimming
• Multiple alarm options including high or low trip,
out of band, rate of change, stuck input and fault
alarm
• Failsafe or non-failsafe, and normally open
or normally closed alarm relays
• Alarm deadband (0-100%) and alarm time delay
• T/C reference junction compensation (on/off)
• Display parameters (scale, engineering units, and
set number of digits after the decimal point)
• Differential or averaging of RTD inputs
• Standard and custom linearization curves
(up to 128 points)*
• Analog output range**
• On input failure, upscale or downscale drive, fail
to last value or fail to selected value**
• Analog signal output damping (0-30 seconds)**
*Programmable via the PC Conﬁguration Software only.
**Models with Analog Output (-AO) option.
Powers a 2-Wire Transmitter
The SPA2
IS (HLPRG: current/voltage input model)
comes standard with 2-wire transmitter excitation that
provides 24Vdc to power the loop. This saves the
cost of specifying and installing an additional
instrument power supply to power a 2-wire transmitter
on the input loop.
Figure 6. In addition to pushbutton conﬁguration, the SPA2
IS
programs quickly from a single software window.
Versatile Alarm Options
Each individually-conﬁgurable SPA2
IS alarm trip relay
programs via the PC software as a:
Band Alarm—Combines the High and the Low Trip
Alarms into one. It can be used to warn of a process
that has left its normal operating conditions.
Stuck Alarm—Monitors the input with respect to time
and trips when that input hasn’t changed by a user-
selected rate (Delta) over a user selected time period
(Delta Time).
High or Low Limit Process Alarm—Monitor a
temperature, pressure, level, ﬂow, position or status
variable, and use to warn of unwanted process
conditions (Figure 4), provide emergency shutdown
or provide on/off control (Figure 5).
Rate-of-Change Alarm—Monitor an input for a
change in value with respect to time (Figure 6). The
alarm trips when the input rate-of-change exceeds a
user-selected rate (Delta) over a user selected time
period (Delta Time).
Input Fault Alarm—Setting one of the alarm’s relays
to trip on input or self-diagnostic failure (without
affecting the other relay being used to monitor the
process) is typically implemented to warn of a failure,
such as a broken sensor, without tripping more critical
process alarms or shutting down the process.
Out of Range Alarm—Monitor your process variable
(PV). If the value strays past user-set limits, the
SPA2
IS will go into an alarm state indicating that the
PV has gone out of the allowed range.
Figure 5. The SPA2
IS provides transmitter excitation to power a
2-wire transmitter.
+TX
+I
+
–
SPA IS
(HLPRG
Input)
24Vdc
Power
Input
2-Wire
Transmitter 4-20mA
Loop Power
2
Hazardous Area
Class I, Div I/Zone 0,1
Safe Area
or Class I, Div 2/Zone 2

5.
Programmable Limit Alarm Trips with
Intrinsically-Safe Field Connections
SPA2
IS
Page 5
Self-Diagnostic Alarm—The SPA2
IS checks its own
operation and conﬁguration upon start up, and then
continuously monitors its status during operation.
One of the SPA2
IS relays can be conﬁgured to trip if
it senses that it is not operating properly.
Quick Ranging Calibration
Using the front panel pushbuttons or the PC
Conﬁguration Software (instead of potentiometers
which can drift), precise zero and span settings can
be made in seconds. Just select the zero and span
values, and the push of a button locks the values into
the alarm trip’s memory.
Figure 7. High and/or low limit alarms, with a selectable deadband
to reduce false alarms, can be used to warn of unwanted process
conditions or to provide emergency shutdown.
Time
Input
Alarm State
Non-Alarm State
LIMIT ALARM TRIP
High
Alarm
Trip Point
Deadband
High AlarmTrip Resets
Low Alarm
Trip Point
Low Alarm
Trip Resets
Deadband
Figure 8. The SPA2
IS can be used as a simple on/off controller
such as those required in level applications (pump/valve control)
when ﬁlling or emptying a container or tank.
Time
Input
ON Trip Point
Relay ON
Relay OFF
ON/OFF CONTROLLER
OFF Trip Point
OFF Trip
Point
Figure 9. The SPA2
IS can be set to trip when the input
rate-of-change exceeds a user-selected rate (Delta) over a
user-selected time period (Delta Time).
Time (t)
Temperature (T)
Alarm State
Non-Alarm State
RATE-OF-CHANGE ALARM
t
> limit
T
t
T
Combination Alarm and Isolated
Transmitter
When ordered with the Analog Output (-AO) option, the
SPA2
IS provides a proportional and isolated analog
retransmission of the input signal that can be sent to
remote monitoring/control devices like a DCS, PLC,
PC, indicator or data recorder (Figure 7). All analog
parameters can be selected using the SPA2
IS push
buttons or the Intelligent PC Conﬁguration Software.
Upon input failure, the analog output can be user-set
for upscale or downscale drive or fail to last value.
Continuous Self-Diagnostics
Incorporating advanced self-diagnostics, the SPA2
IS
checks its own operation and conﬁguration upon start
up and then continuously monitors its status during
operation. If it senses that it is not operating properly,
it displays an error message on its display indicating
what condition has occurred. In addition, one or
more of the alarm trip outputs can be set as a fault
alarm which will trip when an unwanted diagnostic
condition occurs.
Figure 10. When ordered with the Analog Output (-AO) option,
the SPA2
IS is a combination alarm trip and signal transmitter.
Hazardous Area
Class I, Div I/Zone 0,1
Safe Area
or Class I, Div 2/Zone 2
Programmable
Alarm Trips
Isolated
Analog Output
Any Range
Between
0-20mA
Programmable
Input
mA
V
RTD
T/C
ohms
mV

6.
Programmable Limit Alarm Trips with
Intrinsically-Safe Field Connections
SPA2
IS
Page 6
Custom 128-Point Linearization Curves
The ability to plot a custom linearization curve is
beneﬁcial when non-linear input signals must be
converted to linear output representations (Figure 11).
Typical applications include monitoring a non-linear
transducer, the level of odd-shaped tanks and ﬂow
meter linearization.
Figure 11. Using the Intelligent PC Conﬁguration Software, up to
128 custom linearization points can be selected and saved in the
SPA2
IS’s memory to compensate for non-linear input signals.
8mA 12mA 16mA 20mA4mA
Input mA
0%
25%
50%
75%
100%
%Display
Full
Scale
Full
Scale
(6mA, 35%)
(8mA, 50%)
(12mA, 70%)
(16mA, 87%)
(20mA, 100%)
Output = Function of the Input
Custom
Linearization
Points
Lower
(Zero)
Range
Full
(High)
Range
Ideal RTD Curve
(Used By Default)
Actual
Sensor
Curve
100
98
1
0
˚C
Upper Trim
Point #2
Lower Trim
Point #1
27
20
Captured
20˚C-27˚C
Figure 12. The SPA2
IS can be set to measure the segment most
critical to the process.
Trim to Speciﬁc Curve Segments
The SPA2
IS can be trimmed with two data points
within the selected zero and span measurement
range (Figure 12). This allows a complete process
range to be monitored while placing measurement
emphasis on a critical segment of the range. This
provides incredible precision over a limited portion of
the span while measuring the remainder of the span
with outstanding accuracy.
Total Sensor Diagnostics for RTD Inputs
Our SPA2
IS Programmable Limit Alarm Trip (TPRG
input model) performs continuous sensor diagnostics
(Figure 13). This industry-ﬁrst and patented Moore
Industries feature saves you time and money by
letting you know when a problem occurs, and its
type and location. If the RTD input breaks, the user
can decide whether or not to trip one or more alarms
to indicate trouble. A plain-English error message
on the display, as well as on the PC Conﬁguration
Software, indicates exactly which RTD wire has
broken. Speciﬁc error messages eliminate the work
of removing the sensor or checking all lead wires to
diagnose a problem. If equipped with the Analog
Output (-AO) option, the user has the option of driving
the analog output either upscale or downscale on
sensor failure.
Figure 13. Patented “Total Sensor Diagnostics” saves
troubleshooting time by identifying which sensor wire has broken.
Hazardous Area
Class I, Div I/Zone 0,1
Safe Area
or Class I, Div 2/Zone 2
Broken
RTD Wire #1
Display Shows
Which RTD
Wire is Broken
Alarm(s) Trip to
Alert of Sensor
Problem
Analog Output
Drives Upscale
or Downscale
(with -AO Option)
4-Wire
RTD